server/async.c

   1 /*
   2  * Server-side async I/O support
   3  *
   4  * Copyright (C) 2007 Alexandre Julliard
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  19  */
  20
  21 #include <assert.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <stdarg.h>
  25
  26 #include "ntstatus.h"
  27 #define WIN32_NO_STATUS
  28 #include "windef.h"
  29 #include "winternl.h"
  30
  31 #include "object.h"
  32 #include "file.h"
  33 #include "request.h"
  34 #include "process.h"
  35 #include "handle.h"
  36
  37 struct async
  38 {
  39     struct object        obj;             /* object header */
  40     struct thread       *thread;          /* owning thread */
  41     struct list          queue_entry;     /* entry in async queue list */
  42     struct list          process_entry;   /* entry in process list */
  43     struct async_queue  *queue;           /* queue containing this async */
  44     struct fd           *fd;              /* fd associated with an unqueued async */
  45     unsigned int         status;          /* current status */
  46     struct timeout_user *timeout;
  47     unsigned int         timeout_status;  /* status to report upon timeout */
  48     int                  signaled;
  49     struct event        *event;
  50     async_data_t         data;            /* data for async I/O call */
  51     struct iosb         *iosb;            /* I/O status block */
  52     obj_handle_t         wait_handle;     /* pre-allocated wait handle */
  53     int                  direct_result;   /* a flag if we're passing result directly from request instead of APC  */
  54     struct completion   *completion;      /* completion associated with fd */
  55     apc_param_t          comp_key;        /* completion key associated with fd */
  56 };
  57
  58 static void async_dump( struct object *obj, int verbose );
  59 static int async_signaled( struct object *obj, struct wait_queue_entry *entry );
  60 static void async_satisfied( struct object * obj, struct wait_queue_entry *entry );
  61 static void async_destroy( struct object *obj );
  62
  63 static const struct object_ops async_ops =
  64 {
  65     sizeof(struct async),      /* size */
  66     async_dump,                /* dump */
  67     no_get_type,               /* get_type */
  68     add_queue,                 /* add_queue */
  69     remove_queue,              /* remove_queue */
  70     async_signaled,            /* signaled */
  71     async_satisfied,           /* satisfied */
  72     no_signal,                 /* signal */
  73     no_get_fd,                 /* get_fd */
  74     no_map_access,             /* map_access */
  75     default_get_sd,            /* get_sd */
  76     default_set_sd,            /* set_sd */
  77     no_lookup_name,            /* lookup_name */
  78     no_link_name,              /* link_name */
  79     NULL,                      /* unlink_name */
  80     no_open_file,              /* open_file */
  81     no_close_handle,           /* close_handle */
  82     async_destroy              /* destroy */
  83 };
  84
  85 static inline void async_reselect( struct async *async )
  86 {
  87     if (async->queue && async->fd) fd_reselect_async( async->fd, async->queue );
  88 }
  89
  90 static void async_dump( struct object *obj, int verbose )
  91 {
  92     struct async *async = (struct async *)obj;
  93     assert( obj->ops == &async_ops );
  94     fprintf( stderr, "Async thread=%p\n", async->thread );
  95 }
  96
  97 static int async_signaled( struct object *obj, struct wait_queue_entry *entry )
  98 {
  99     struct async *async = (struct async *)obj;
 100     assert( obj->ops == &async_ops );
 101     return async->signaled;
 102 }
 103
 104 static void async_satisfied( struct object *obj, struct wait_queue_entry *entry )
 105 {
 106     struct async *async = (struct async *)obj;
 107     assert( obj->ops == &async_ops );
 108
 109     if (async->direct_result)
 110     {
 111         async_set_result( &async->obj, async->iosb->status, async->iosb->result );
 112         async->direct_result = 0;
 113     }
 114
 115     /* close wait handle here to avoid extra server round trip */
 116     if (async->wait_handle)
 117     {
 118         close_handle( async->thread->process, async->wait_handle );
 119         async->wait_handle = 0;
 120     }
 121 }
 122
 123 static void async_destroy( struct object *obj )
 124 {
 125     struct async *async = (struct async *)obj;
 126     assert( obj->ops == &async_ops );
 127
 128     list_remove( &async->process_entry );
 129
 130     if (async->queue)
 131     {
 132         list_remove( &async->queue_entry );
 133         async_reselect( async );
 134     }
 135     else if (async->fd) release_object( async->fd );
 136
 137     if (async->timeout) remove_timeout_user( async->timeout );
 138     if (async->completion) release_object( async->completion );
 139     if (async->event) release_object( async->event );
 140     if (async->iosb) release_object( async->iosb );
 141     release_object( async->thread );
 142 }
 143
 144 /* notifies client thread of new status of its async request */
 145 void async_terminate( struct async *async, unsigned int status )
 146 {
 147     assert( status != STATUS_PENDING );
 148
 149     if (async->status != STATUS_PENDING)
 150     {
 151         /* already terminated, just update status */
 152         async->status = status;
 153         return;
 154     }
 155
 156     async->status = status;
 157     if (async->iosb && async->iosb->status == STATUS_PENDING) async->iosb->status = status;
 158
 159     if (!async->direct_result)
 160     {
 161         if (async->data.user)
 162         {
 163             apc_call_t data;
 164
 165             memset( &data, 0, sizeof(data) );
 166             data.type            = APC_ASYNC_IO;
 167             data.async_io.user   = async->data.user;
 168             data.async_io.sb     = async->data.iosb;
 169             data.async_io.status = status;
 170             thread_queue_apc( async->thread, &async->obj, &data );
 171         }
 172         else async_set_result( &async->obj, STATUS_SUCCESS, 0 );
 173     }
 174
 175     async_reselect( async );
 176     if (async->queue) release_object( async );  /* so that it gets destroyed when the async is done */
 177 }
 178
 179 /* callback for timeout on an async request */
 180 static void async_timeout( void *private )
 181 {
 182     struct async *async = private;
 183
 184     async->timeout = NULL;
 185     async_terminate( async, async->timeout_status );
 186 }
 187
 188 /* free an async queue, cancelling all async operations */
 189 void free_async_queue( struct async_queue *queue )
 190 {
 191     struct async *async, *next;
 192
 193     LIST_FOR_EACH_ENTRY_SAFE( async, next, &queue->queue, struct async, queue_entry )
 194     {
 195         async->completion = fd_get_completion( async->fd, &async->comp_key );
 196         async->fd = NULL;
 197         async_terminate( async, STATUS_HANDLES_CLOSED );
 198         async->queue = NULL;
 199     }
 200 }
 201
 202 void queue_async( struct async_queue *queue, struct async *async )
 203 {
 204     /* fd will be set to NULL in free_async_queue when fd is destroyed */
 205     release_object( async->fd );
 206
 207     async->queue = queue;
 208     grab_object( async );
 209     list_add_tail( &queue->queue, &async->queue_entry );
 210
 211     if (async->fd) set_fd_signaled( async->fd, 0 );
 212 }
 213
 214 /* create an async on a given queue of a fd */
 215 struct async *create_async( struct fd *fd, struct thread *thread, const async_data_t *data, struct iosb *iosb )
 216 {
 217     struct event *event = NULL;
 218     struct async *async;
 219
 220     if (data->event && !(event = get_event_obj( thread->process, data->event, EVENT_MODIFY_STATE )))
 221         return NULL;
 222
 223     if (!(async = alloc_object( &async_ops )))
 224     {
 225         if (event) release_object( event );
 226         return NULL;
 227     }
 228
 229     async->thread        = (struct thread *)grab_object( thread );
 230     async->event         = event;
 231     async->status        = STATUS_PENDING;
 232     async->data          = *data;
 233     async->timeout       = NULL;
 234     async->queue         = NULL;
 235     async->fd            = (struct fd *)grab_object( fd );
 236     async->signaled      = 0;
 237     async->wait_handle   = 0;
 238     async->direct_result = 0;
 239     async->completion    = NULL;
 240
 241     if (iosb) async->iosb = (struct iosb *)grab_object( iosb );
 242     else async->iosb = NULL;
 243
 244     list_add_head( &thread->process->asyncs, &async->process_entry );
 245     if (event) reset_event( event );
 246
 247     return async;
 248 }
 249
 250 /* create an async associated with iosb for async-based requests
 251  * returned async must be passed to async_handoff */
 252 struct async *create_request_async( struct fd *fd, const async_data_t *data )
 253 {
 254     struct async *async;
 255     struct iosb *iosb;
 256
 257     if (!(iosb = create_iosb( get_req_data(), get_req_data_size(), get_reply_max_size() )))
 258         return NULL;
 259
 260     async = create_async( fd, current, data, iosb );
 261     release_object( iosb );
 262     if (async)
 263     {
 264         if (!(async->wait_handle = alloc_handle( current->process, async, SYNCHRONIZE, 0 )))
 265         {
 266             release_object( async );
 267             return NULL;
 268         }
 269         async->direct_result = 1;
 270     }
 271     return async;
 272 }
 273
 274 /* return async object status and wait handle to client */
 275 obj_handle_t async_handoff( struct async *async, int success, data_size_t *result )
 276 {
 277     if (!success)
 278     {
 279         close_handle( async->thread->process, async->wait_handle );
 280         async->wait_handle = 0;
 281         return 0;
 282     }
 283
 284     if (get_error() != STATUS_PENDING)
 285     {
 286         /* status and data are already set and returned */
 287         async_terminate( async, get_error() );
 288     }
 289     else if (async->iosb->status != STATUS_PENDING)
 290     {
 291         /* result is already available in iosb, return it */
 292         if (async->iosb->out_data)
 293         {
 294             set_reply_data_ptr( async->iosb->out_data, async->iosb->out_size );
 295             async->iosb->out_data = NULL;
 296         }
 297     }
 298
 299     if (async->iosb->status != STATUS_PENDING)
 300     {
 301         if (result) *result = async->iosb->result;
 302         async->signaled = 1;
 303     }
 304     else
 305     {
 306         async->direct_result = 0;
 307         if (!async_is_blocking( async ))
 308         {
 309             close_handle( async->thread->process, async->wait_handle);
 310             async->wait_handle = 0;
 311         }
 312     }
 313     set_error( async->iosb->status );
 314     return async->wait_handle;
 315 }
 316
 317 /* set the timeout of an async operation */
 318 void async_set_timeout( struct async *async, timeout_t timeout, unsigned int status )
 319 {
 320     if (async->timeout) remove_timeout_user( async->timeout );
 321     if (timeout != TIMEOUT_INFINITE) async->timeout = add_timeout_user( timeout, async_timeout, async );
 322     else async->timeout = NULL;
 323     async->timeout_status = status;
 324 }
 325
 326 static void add_async_completion( struct async *async, apc_param_t cvalue, unsigned int status,
 327                                   apc_param_t information )
 328 {
 329     if (async->fd && !async->completion) async->completion = fd_get_completion( async->fd, &async->comp_key );
 330     if (async->completion) add_completion( async->completion, async->comp_key, cvalue, status, information );
 331 }
 332
 333 /* store the result of the client-side async callback */
 334 void async_set_result( struct object *obj, unsigned int status, apc_param_t total )
 335 {
 336     struct async *async = (struct async *)obj;
 337
 338     if (obj->ops != &async_ops) return;  /* in case the client messed up the APC results */
 339
 340     assert( async->status != STATUS_PENDING );  /* it must have been woken up if we get a result */
 341
 342     if (status == STATUS_PENDING)  /* restart it */
 343     {
 344         status = async->status;
 345         async->status = STATUS_PENDING;
 346         grab_object( async );
 347
 348         if (status != STATUS_ALERTED)  /* it was terminated in the meantime */
 349             async_terminate( async, status );
 350         else
 351             async_reselect( async );
 352     }
 353     else
 354     {
 355         if (async->timeout) remove_timeout_user( async->timeout );
 356         async->timeout = NULL;
 357         async->status = status;
 358         if (status == STATUS_MORE_PROCESSING_REQUIRED) return;  /* don't report the completion */
 359
 360         if (async->data.apc)
 361         {
 362             apc_call_t data;
 363             memset( &data, 0, sizeof(data) );
 364             data.type         = APC_USER;
 365             data.user.func    = async->data.apc;
 366             data.user.args[0] = async->data.apc_context;
 367             data.user.args[1] = async->data.iosb;
 368             data.user.args[2] = 0;
 369             thread_queue_apc( async->thread, NULL, &data );
 370         }
 371         else if (async->data.apc_context)
 372             add_async_completion( async, async->data.apc_context, status, total );
 373
 374         if (async->event) set_event( async->event );
 375         else if (async->fd) set_fd_signaled( async->fd, 1 );
 376         if (!async->signaled)
 377         {
 378             async->signaled = 1;
 379             wake_up( &async->obj, 0 );
 380         }
 381     }
 382 }
 383
 384 /* check if an async operation is waiting to be alerted */
 385 int async_waiting( struct async_queue *queue )
 386 {
 387     struct list *ptr;
 388     struct async *async;
 389
 390     if (!(ptr = list_head( &queue->queue ))) return 0;
 391     async = LIST_ENTRY( ptr, struct async, queue_entry );
 392     return async->status == STATUS_PENDING;
 393 }
 394
 395 static int cancel_async( struct process *process, struct object *obj, struct thread *thread, client_ptr_t iosb )
 396 {
 397     struct async *async;
 398     int woken = 0;
 399
 400 restart:
 401     LIST_FOR_EACH_ENTRY( async, &process->asyncs, struct async, process_entry )
 402     {
 403         if (async->status == STATUS_CANCELLED) continue;
 404         if ((!obj || (async->fd && get_fd_user( async->fd ) == obj)) &&
 405             (!thread || async->thread == thread) &&
 406             (!iosb || async->data.iosb == iosb))
 407         {
 408             async_terminate( async, STATUS_CANCELLED );
 409             woken++;
 410             goto restart;
 411         }
 412     }
 413     return woken;
 414 }
 415
 416 void cancel_process_asyncs( struct process *process )
 417 {
 418     cancel_async( process, NULL, NULL, 0 );
 419 }
 420
 421 /* wake up async operations on the queue */
 422 void async_wake_up( struct async_queue *queue, unsigned int status )
 423 {
 424     struct list *ptr, *next;
 425
 426     LIST_FOR_EACH_SAFE( ptr, next, &queue->queue )
 427     {
 428         struct async *async = LIST_ENTRY( ptr, struct async, queue_entry );
 429         async_terminate( async, status );
 430         if (status == STATUS_ALERTED) break;  /* only wake up the first one */
 431     }
 432 }
 433
 434 static void iosb_dump( struct object *obj, int verbose );
 435 static void iosb_destroy( struct object *obj );
 436
 437 static const struct object_ops iosb_ops =
 438 {
 439     sizeof(struct iosb),      /* size */
 440     iosb_dump,                /* dump */
 441     no_get_type,              /* get_type */
 442     no_add_queue,             /* add_queue */
 443     NULL,                     /* remove_queue */
 444     NULL,                     /* signaled */
 445     NULL,                     /* satisfied */
 446     no_signal,                /* signal */
 447     no_get_fd,                /* get_fd */
 448     no_map_access,            /* map_access */
 449     default_get_sd,           /* get_sd */
 450     default_set_sd,           /* set_sd */
 451     no_lookup_name,           /* lookup_name */
 452     no_link_name,             /* link_name */
 453     NULL,                     /* unlink_name */
 454     no_open_file,             /* open_file */
 455     no_close_handle,          /* close_handle */
 456     iosb_destroy              /* destroy */
 457 };
 458
 459 static void iosb_dump( struct object *obj, int verbose )
 460 {
 461     assert( obj->ops == &iosb_ops );
 462     fprintf( stderr, "I/O status block\n" );
 463 }
 464
 465 static void iosb_destroy( struct object *obj )
 466 {
 467     struct iosb *iosb = (struct iosb *)obj;
 468
 469     free( iosb->in_data );
 470     free( iosb->out_data );
 471 }
 472
 473 /* allocate iosb struct */
 474 struct iosb *create_iosb( const void *in_data, data_size_t in_size, data_size_t out_size )
 475 {
 476     struct iosb *iosb;
 477
 478     if (!(iosb = alloc_object( &iosb_ops ))) return NULL;
 479
 480     iosb->status = STATUS_PENDING;
 481     iosb->result = 0;
 482     iosb->in_size = in_size;
 483     iosb->in_data = NULL;
 484     iosb->out_size = out_size;
 485     iosb->out_data = NULL;
 486
 487     if (in_size && !(iosb->in_data = memdup( in_data, in_size )))
 488     {
 489         release_object( iosb );
 490         iosb = NULL;
 491     }
 492
 493     return iosb;
 494 }
 495
 496 struct iosb *async_get_iosb( struct async *async )
 497 {
 498     return async->iosb ? (struct iosb *)grab_object( async->iosb ) : NULL;
 499 }
 500
 501 int async_is_blocking( struct async *async )
 502 {
 503     return !async->event && !async->data.apc && !async->data.apc_context;
 504 }
 505
 506 /* find the first pending async in queue */
 507 struct async *find_pending_async( struct async_queue *queue )
 508 {
 509     struct async *async;
 510     LIST_FOR_EACH_ENTRY( async, &queue->queue, struct async, queue_entry )
 511         if (async->status == STATUS_PENDING) return (struct async *)grab_object( async );
 512     return NULL;
 513 }
 514
 515 /* cancels all async I/O */
 516 DECL_HANDLER(cancel_async)
 517 {
 518     struct object *obj = get_handle_obj( current->process, req->handle, 0, NULL );
 519     struct thread *thread = req->only_thread ? current : NULL;
 520
 521     if (obj)
 522     {
 523         int count = cancel_async( current->process, obj, thread, req->iosb );
 524         if (!count && req->iosb) set_error( STATUS_NOT_FOUND );
 525         release_object( obj );
 526     }
 527 }
 528
 529 /* get async result from associated iosb */
 530 DECL_HANDLER(get_async_result)
 531 {
 532     struct iosb *iosb = NULL;
 533     struct async *async;
 534
 535     LIST_FOR_EACH_ENTRY( async, &current->process->asyncs, struct async, process_entry )
 536         if (async->data.user == req->user_arg)
 537         {
 538             iosb = async->iosb;
 539             break;
 540         }
 541
 542     if (!iosb)
 543     {
 544         set_error( STATUS_INVALID_PARAMETER );
 545         return;
 546     }
 547
 548     if (iosb->out_data)
 549     {
 550         data_size_t size = min( iosb->out_size, get_reply_max_size() );
 551         if (size)
 552         {
 553             set_reply_data_ptr( iosb->out_data, size );
 554             iosb->out_data = NULL;
 555         }
 556     }
 557     reply->size = iosb->result;
 558     set_error( iosb->status );
 559 }